In a self-winding watch, the movements of the wearer are transmitted to the spring barrel by means of an oscillating mass and a reduction mechanism. This mass can be fixed to the centre of the movement or possibly off-centre. Generally the self-winding mechanism is placed above the movement, on the bridge side. However it frequently happens likewise that the oscillating mass is disposed below the movement. The works of the self-winding mechanism are composed of toothed elements, which make it possible to transmit the force from the oscillating mass to the ratchet and to wind up the spring barrel. The works of this self-winding mechanism are composed generally of the following elements: pinion of the oscillating mass, intermediate direction-adjusting moving elements, reduction and ratchet moving elements. The works of the self-winding mechanism are composed in general of a gear mechanism part and a stepping down mechanism part, also termed reduction mechanism. It is the latter which has the object of reducing the initial speed of the oscillating mass and of increasing the force intended for winding up the spring barrel.
Certain manufacturers provide self-winding watches with a device for indicating the power reserve, i.e. a device which makes it possible for the wearer to know at any time the number of hours during which the watch will still function without being wound up. The power reserve is then indicated either by a disc carrying numbers, one of which is visible through a window, or by means of a needle which is displaced above a supplementary graduation.
The combination of a self-winding mechanism with an indicator of the power reserve is reserved more for expensive watches, normally termed smart watches. Such watches can comprise, apart from the mechanism for displaying the power reserve, a stop-watch, a day of the month mechanism, a mechanism indicating phases of the moon or others, so that the space available on the face of such watches for indicating the power reserve is reduced.
The object of the present invention is to remedy this disadvantage by providing the mechanism for indicating the power reserve at a place on the watch where more space is available.